arm: dt: zed: fixing xadc register area

Removed the extra zero in the register area size.

Signed-off-by: Veena Kumar <veena.kumar@xilinx.com>
Reviewed-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>